Bonjour;
a. 7×(2x-1)=8x+5
14x -7 = 8x+5
14x-8x = 5+7
6x = 12
x= 12/6
x=2
b. 8a-2=3x(4a-5)
8a-2 = 12a -15
-2 +15 = 12a -8a
13 = 4a
a = 13/4
c. 2x (3b+7)=5x(-2b+1)
6b +14 = -10b +5
6b+10b = 5-14
16b = -9
b = -9/16
d. 3×(-1-2t) = 4 × (1 − 5t)
-3 -6t = 4 -20t
20t -6t =4+3
14t = 7
t = 7/14
t = 1/7